The situation is similar with violas. There's a maker[0] who builds wildly asymmetric violas that have pretty good sound and are ergonomically excellent — very easy to play — but they're generally unwelcome in orchestras because their unorthodox appearance is distracting. Instrument makers consistently report that players will imagine all sorts of sound and playability problems when they try out an ugly instrument. I'm sure the author's guess about flute is correct: people like an instrument that looks right to them and to the audience.